On Sun 2009-05-03 18:22:54, Rafael J. Wysocki wrote: > On Sunday 03 May 2009, Wu Fengguang wrote: > > On Sun, May 03, 2009 at 02:24:20AM +0200, Rafael J. Wysocki wrote: > > > From: Rafael J. Wysocki <rjw@xxxxxxx> > > > > > > Modify the hibernation memory shrinking code so that it will make > > > memory allocations to free memory instead of using an artificial > > > memory shrinking mechanism for that. Remove the shrinking of > > > memory from the suspend-to-RAM code, where it is not really > > > necessary. Finally, remove the no longer used memory shrinking > > > functions from mm/vmscan.c . > > > > > > [rev. 2: Use the existing memory bitmaps for marking preallocated > > > image pages and use swsusp_free() from releasing them, introduce > > > GFP_IMAGE, add comments describing the memory shrinking strategy.] > > > > > > Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> > > > --- > > > kernel/power/main.c | 20 ------ > > > kernel/power/snapshot.c | 132 +++++++++++++++++++++++++++++++++----------- > > > mm/vmscan.c | 142 ------------------------------------------------ > > > 3 files changed, 101 insertions(+), 193 deletions(-) > > > > > > Index: linux-2.6/kernel/power/snapshot.c > > > =================================================================== > > > --- linux-2.6.orig/kernel/power/snapshot.c > > > +++ linux-2.6/kernel/power/snapshot.c > > > @@ -1066,41 +1066,97 @@ void swsusp_free(void) > > > buffer = NULL; > > > } > > > > > > +/* Helper functions used for the shrinking of memory. */ > > > + > > > +#ifdef CONFIG_HIGHMEM > > > +#define GFP_IMAGE (GFP_KERNEL | __GFP_HIGHMEM | __GFP_NO_OOM_KILL) > > > +#else > > > +#define GFP_IMAGE (GFP_KERNEL | __GFP_NO_OOM_KILL) > > > +#endif > > > > The CONFIG_HIGHMEM test is not necessary: __GFP_HIGHMEM is always defined. > > > > > +#define SHRINK_BITE 10000 > > > > This is ~40MB. A full scan of (for example) 8G pages will be time > > consuming, not to mention we have to do it 2*(8G-500M)/40M = 384 times! > > > > Can we make it a LONG_MAX? > > No, I don't think so. The problem is the number of pages we'll need to copy > is generally shrinking as we allocate memory, so we can't do that in one shot. > > We can make it a greater number, but I don't really think it would be a good > idea to make it greater than 100 MB. Well, even 100MB is quite big: on 128MB machine, that will probably mean freeing all the memory (instead of "as much as needed"). And that memory needs to go to disk, so it will be slow. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
